1. Field of the Invention
This invention relates to a structure of plasma display panels and a method of manufacturing the plasma display panels.
2. Description of the Related Art
A surface-discharge-type alternating-current plasma display panel (hereinafter referred to as “PDP”) has two opposing glass substrates placed on either side of a discharge-gas-filled discharge space. On one of the two glass substrates, row electrode pairs extending in the row direction are regularly arranged in the column direction. On the other glass substrate, column electrodes extending in the column direction are regularly arranged in the row direction. Unit light emission areas (discharge cells) are formed in matrix form in positions corresponding to the intersections between the row electrode pairs and the column electrodes in the discharge space.
The PDP further has a dielectric layer provided for covering the row electrodes or the column electrodes. A magnesium oxide (MgO) film is formed on a portion of the dielectric layer facing each of the unit light emission areas . The MgO film has the function of protecting the dielectric layer and the function of emitting secondary electrons into the unit light emission area.
As a method of forming the magnesium oxide film in the manufacturing process for the PDP as described above, the use of a screen printing technique of coating a paste containing magnesium oxide powder on the dielectric layer to form a magnesium oxide film has been considered for adoption in terms of simplicity and convenience.
Such a conventional method of forming the magnesium oxide film is disclosed in Japanese Patent Laid-open Publication No. H6-325696, for example.
However, the discharge characteristics of a PDP having a magnesium oxide formed by a screen printing technique using a paste containing a polycrystalline floccules type magnesium oxide refined by heat-treating magnesium hydroxide is merely of an extent equal to or slightly greater than that of a PDP having a magnesium oxide film formed by the use of evaporation technique.
A need arising from this is to form a magnesium oxide film (i.e. a protective film) capable of yielding a greater improvement in the discharge characteristics in the PDP.